Plastic heat exchanger

An intermediate article useful in the manufacture of a heat exchanger core comprising:

• first and second one-piece thermoplastic end plates each of which includes a thin planar wall and a plurality of closed pockets extending from a common side of said wall, each of said pockets including a tubular sidewall of uniform cross section throughout its length and an abutment surface extending perpendicularly from said sidewall, each said abutment surface comprising a continuous planar floor connected to the entire periphery of said sidewall to close each of said pockets, the depth of all of said pockets from said wall to said abutment surface being uniform, said first and second plates being oriented such that the pockets of one plate open towards the other plate;
• and
• a plurality of thermoplastic tubular members each of uniform cross section throughout its length and each of which includes a first end extending through said first think planar wall and closely received within one of said first end wall pockets abutting the associated abutment surface and a second end extending through said second thin planar wall and closely received within one of said second end wall pockets abutting the associated abutment surface, whereby said tubes are uniformly registered with respect to both of said end plates, and further whereby severing each pocket and tube positioned therein will expose said tubes through said end plate.